Uganda's President Yoweri Museveni speaks during a campaign rally in KampalaJames Akena/Reuters

Uganda President Yoweri Museveni's decision to invite his Sudanese counterpart Omar al-Bashir, wanted by the International Criminal Court (ICC) on charges of genocide, war crimes, and crimes against humanity, to his swearing-in ceremony has been widely criticised.

Bashir is expected to attend the inauguration ceremony of Museveni for another five-year term, which is to be held on Thursday (12 May) in the Ugandan capital, Kampala. Museveni was declared the victor following disputed presidential elections in February.

"Uganda's President Museveni has banned social media and detained some opposition leaders, but he'll tarnish his inauguration further by welcoming Sudanese President Omar al-Bashir, an international fugitive sought for alleged atrocities in Darfur," Maria Burnett, senior Africa researcher at Human Rights Watch (HRW) said.

"Bashir belongs before the ICC, not attending inaugural celebrations. If al-Bashir does enter Uganda, Ugandan authorities should arrest him and send him to The Hague."

Meanwhile n Kampala, police arrested Kizza Besigye, the main opposition leader who came second in the February elections, a day before the ceremony. He was detained as he greeted supporters during a surprise public appearance in the capital.

Al-Bashir faces two ICC arrest warrants

Sudanese President Omar Hassan al Bashir departs after attending Kenya's promulgation of the new constitution at the Uhuru Park grounds in Nairobi August 27, 2010REUTERS

The ICC issued a first warrant for Bashir in 2009 for war crimes and crimes against humanity in Darfur. In 2010, he was handed another warrant for the crime of genocide linked to the mass slaughter and rape of Darfuri men, women and children in Western Sudan -it was the first time the ICC had issued an arrest warrant for genocide.

Bashir has always rejected the charges and refuses to stand trial as his country does not recognise the ICC's jurisdiction.

HRW found that the highest levels of the Sudanese leadership, including Bashir, are responsible for attacks, which "deliberately and systematically targeted civilians in violation of international law, as part of the Sudan government's counter-insurgency policy in Darfur. The rights group describes the crimes in Darfur as ethnic cleansing, war crimes, and crimes against humanity.

Following his 2010 warrant, Elise Keppler, senior counsel with the International Justice Program at HRW said: "President Bashir's stonewalling on the initial ICC warrant against him appears only more outrageous now that he's also being sought for genocide."

She added: "Security Council members and other concerned governments should actively press Sudan to stop its blatant obstruction of the ICC and to see to it that al-Bashir appears at the court."

Bashir avoids arrests

So far, the Sudanese leader has avoided arrest for the alleged international crimes.

A United Nations Security Council resolution requires Sudan to cooperate with the ICC investigation, but Khartoum has impeded its efforts. Civil society groups – particularly in Africa – have called for Bashir's arrest and for governments to ensure he faces justice.

While many countries have chosen not to welcome Bashir on their soil. However, in 2015, South Africa became embroiled in a bitter dispute with the international court after it allowed Bashir to leave the country following an African Union summit.

Its courts did eventually order the Sudanese premier's arrest, stating he was not protected by diplomatic immunity, but Bashir had already fled the country hours earlier on a jet from a military base.